feat: bulk remove bookmarks with undo snackbar restoring bookmarks and notes

Co-Authored-By: Claude <noreply@anthropic.com>

feature/bookmarks/impl/src/main/kotlin/com/google/samples/apps/nowinandroid/feature/bookmarks/impl/BookmarksScreen.kt

@@ -126,6 +126,10 @@ internal fun BookmarksScreen(
         exitSelectionMode = viewModel::exitSelectionMode,
         toggleSelection = viewModel::toggleSelection,
         selectAll = viewModel::selectAll,
+        shouldDisplayUndoBulkRemove = viewModel.shouldDisplayUndoBulkRemove,
+        removeSelected = viewModel::removeSelected,
+        undoBulkRemove = viewModel::undoBulkRemove,
+        clearBulkUndoState = viewModel::clearBulkUndoState,
     )
 
     editingNoteId?.let { id ->
@@ -163,9 +167,14 @@ internal fun BookmarksScreen(
     exitSelectionMode: () -> Unit = {},
     toggleSelection: (String) -> Unit = {},
     selectAll: () -> Unit = {},
+    shouldDisplayUndoBulkRemove: Boolean = false,
+    removeSelected: () -> Unit = {},
+    undoBulkRemove: () -> Unit = {},
+    clearBulkUndoState: () -> Unit = {},
 ) {
     val bookmarkRemovedMessage = stringResource(id = R.string.feature_bookmarks_api_removed)
     val undoText = stringResource(id = R.string.feature_bookmarks_api_undo)
+    val removedCount = remember { androidx.compose.runtime.mutableIntStateOf(0) }
 
     BackHandler(enabled = isInSelectionMode) {
         exitSelectionMode()
@@ -182,6 +191,20 @@ internal fun BookmarksScreen(
         }
     }
 
+    LaunchedEffect(shouldDisplayUndoBulkRemove) {
+        if (shouldDisplayUndoBulkRemove) {
+            val result = onShowSnackbar(
+                "${removedCount.intValue} bookmarks removed",
+                undoText,
+            )
+            if (result) {
+                undoBulkRemove()
+            } else {
+                clearBulkUndoState()
+            }
+        }
+    }
+
     LifecycleEventEffect(Lifecycle.Event.ON_STOP) {
         clearUndoState()
     }
@@ -222,7 +245,10 @@ internal fun BookmarksScreen(
 
         if (isInSelectionMode && selectedIds.isNotEmpty()) {
             Button(
-                onClick = { selectedIds.forEach { removeFromBookmarks(it) } },
+                onClick = {
+                    removedCount.intValue = selectedIds.size
+                    removeSelected()
+                },
                 modifier = Modifier
                     .align(Alignment.BottomCenter)
                     .padding(16.dp),

feature/bookmarks/impl/src/main/kotlin/com/google/samples/apps/nowinandroid/feature/bookmarks/impl/BookmarksViewModel.kt

@@ -107,6 +107,43 @@ class BookmarksViewModel @Inject constructor(
         lastRemovedBookmarkId = null
     }
 
+    var shouldDisplayUndoBulkRemove by mutableStateOf(false)
+        private set
+
+    private var bulkRemoveSnapshot: List<Pair<String, String?>> = emptyList()
+
+    fun removeSelected() {
+        val currentFeed = (feedUiState.value as? NewsFeedUiState.Success)?.feed ?: return
+        bulkRemoveSnapshot = selectedIds.map { id ->
+            id to currentFeed.find { it.id == id }?.bookmarkNote
+        }
+        val toRemove = selectedIds.toSet()
+        viewModelScope.launch {
+            toRemove.forEach { id ->
+                userDataRepository.setNewsResourceBookmarked(id, false)
+            }
+        }
+        exitSelectionMode()
+        shouldDisplayUndoBulkRemove = true
+    }
+
+    fun undoBulkRemove() {
+        viewModelScope.launch {
+            bulkRemoveSnapshot.forEach { (id, note) ->
+                userDataRepository.setNewsResourceBookmarked(id, true)
+                if (!note.isNullOrBlank()) {
+                    userDataRepository.setBookmarkNote(id, note)
+                }
+            }
+        }
+        clearBulkUndoState()
+    }
+
+    fun clearBulkUndoState() {
+        shouldDisplayUndoBulkRemove = false
+        bulkRemoveSnapshot = emptyList()
+    }
+
     fun updateNote(newsResourceId: String, note: String) {
         viewModelScope.launch {
             if (note.isNotBlank()) {

feature/bookmarks/impl/src/test/kotlin/com/google/samples/apps/nowinandroid/feature/bookmarks/impl/BookmarksViewModelTest.kt

@@ -136,6 +136,24 @@ class BookmarksViewModelTest {
         assertTrue(viewModel.selectedIds.isEmpty())
     }
 
+    @Test
+    fun removeSelected_capturesSnapshotBeforeRemoval() = runTest {
+        backgroundScope.launch(UnconfinedTestDispatcher()) { viewModel.feedUiState.collect() }
+
+        newsRepository.sendNewsResources(newsResourcesTestData)
+        userDataRepository.setNewsResourceBookmarked(newsResourcesTestData[0].id, true)
+        userDataRepository.setNewsResourceBookmarked(newsResourcesTestData[1].id, true)
+
+        viewModel.enterSelectionMode(newsResourcesTestData[0].id)
+        viewModel.toggleSelection(newsResourcesTestData[1].id)
+
+        viewModel.removeSelected()
+
+        assertTrue(viewModel.shouldDisplayUndoBulkRemove)
+        assertFalse(viewModel.isInSelectionMode)
+        assertTrue(viewModel.selectedIds.isEmpty())
+    }
+
     @Test
     fun feedUiState_undoneBookmarkRemoval_bookmarkIsRestored() = runTest {
         backgroundScope.launch(UnconfinedTestDispatcher()) { viewModel.feedUiState.collect() }